Heat shock proteins (HSPs) are normal intracellular proteins that are produced in greater amounts when cells are subjected to stress or injury. These proteins have been shown to play a key role in the modulation of the secondary injury that occurs after the initial spinal cord injury (SCI). Heat shock proteins normally act as molecular chaperones and are called protein guardians because they act to repair partially damaged proteins. Normally intracellular, HSPs can also be liberated into the systemic circulation to act as important inflammatory mediators. In the setting of SCI, HSP induction has been shown to be beneficial. These proteins are liberated primarily by acutely stressed microglial, endothelial, and ependymal cells. Heat shock proteins have also been shown to assist in the protection of motor neurons and to prevent chronic inflammation after SCI. In animal models, several experimental drugs have shown neuroprotective effects in the spinal cord and appear to function by modulating HSPs.
Sangala Jaypal Reddy, Frank La Marca and Paul Park
Jaypal Reddy Sangala, Elias Dakwar, Juan Uribe and Fernando Vale
The aim of this study was to review the current evidence-based nonsurgical management strategies of ankylosing spondylitis (AS) for spine surgeons. Whereas surgical management is indicated in a highly selected group, nonsurgical management is itself a useful measure for nearly all patients with AS.
The authors conducted a literature review of PubMed using relevant search words. All the articles published in English in the last 15 years were reviewed and the level of evidence provided by them was noted.
Nonpharmacological treatments in the form of physical therapy and patient education have Level Ib evidence in maintaining function in AS. There is Level Ib evidence supporting the use of nonsteroidal antiinflammatory drugs (NSAIDs) and coxibs for treatment in patients with symptoms. There is not enough evidence to support the use of conventional disease-modifying antirheumatoid arthritis drugs. Tumor necrosis factor (TNF)α inhibitors (infliximab, etanercept, and adalimumab) are associated with Level Ib evidence in improving spinal pain, function, inflammatory biomarkers, and spinal inflammation detected by magnetic resonance imaging in patients in whom symptom duration has exceeded 3 months.
Physical therapy and patient education are useful for all patients diagnosed with AS. If symptomatic, patients are started with either a course of nonselective NSAIDs or a selective cyclooxygenase-2 inhibitor. The role of NSAIDs as a disease-modifying therapy in the treatment of AS is increasingly being understood. The central role of TNF in the pathogenesis of AS is now known, and the advent of biological treatment in the form of anti–TNFα factors has revolutionized the medical management of AS and is used in patients with axial disease whose symptoms persist despite an adequate dose of NSAIDs.
Sangala Jaypal Reddy, Wajd N. Al-Holou, Jean-Christophe Leveque, Frank La Marca and Paul Park
Primary traumatic facet dislocations are unusual in the lumbar spine. Most occurrences have been reported at the lumbosacral junction associated with anterior subluxation. The authors describe 2 cases in which a high impact trauma resulted in lateral subluxation with a unilateral locked facet involving the lumbar spine. In their review of the literature, the authors found no previously reported cases of this type of injury. Both cases described in this report involved significant spinal stenosis, neurological injury, and spinal instability. A posterior surgical approach, with at least partial resection of the locked facet joint in conjunction with pedicle screw fixation, allowed successful reduction and stabilization of the injury.
Paul Park, Anthony C. Wang, Jaypal Reddy Sangala, Sung Moon Kim, Shawn Hervey-Jumper, Khoi D. Than, Amin Farokhrani and Frank LaMarca
Surgical correction of symptomatic cervical or cervicothoracic kyphosis involves the potential for significant neurological complications. Intraoperative monitoring has been shown to reduce the risk of neurological injury in scoliosis surgery, but it has not been well evaluated during surgery for cervical or cervicothoracic kyphosis. In this article, the authors review a cohort of patients who underwent kyphosis correction with multimodal intraoperative monitoring (MIOM).
Twenty-nine patients were included in the study. Preoperative and postoperative Cobb angles were measured to determine the extent of correction. Multimodal intraoperative monitoring consisted of somatosensory evoked potentials, transcranial motor evoked potentials (tMEPs), and electromyography activity. Sensitivity, specificity, positive predictive values (PPVs), and negative predictive values (NPVs) were assessed for each monitoring modality.
The mean patient age was 58.0 years, and 20 patients were female. The mean pre- and postoperative sagittal Cobb angles were 41.3° and 7.3°, respectively. A total of 8 intraoperative monitoring alerts were observed. Transcranial MEPs yielded a sensitivity of 75%, specificity of 84%, PPV of 43%, and NPV of 95%. Somatosensory evoked potentials had a sensitivity of 25%, specificity of 96%, PPV of 50%, and NPV of 88%. Electromyography resulted in a sensitivity of 0%, specificity of 93%, PPV of 0%, and NPV of 96%. Changes in tMEPs led to successful intervention in 2 cases. There was 1 case in which a C-8 palsy occurred without any changes in MIOM.
In contrast to sensitivity and PPV, specificity and NPV were generally high in all 3 monitoring modalities. Both false-positive and false-negative results occurred. Transcranial MEP monitoring was the most useful modality and appeared to allow successful intervention in certain cases. Larger, prospective comparative studies are necessary to determine whether MIOM truly decreases the rate of neurological complications and is therefore worth the added economic cost and intraoperative time.